History, mentionings from the forums etc.

Information from the Spyderco catalog on the web

C85GBK:

"The Yojimbo is Spyderco's second collaboration with famed martial artist and Master MBC Instructor Michael Janich. Our first was the fixed-blade called the Ronin. It was avidly received by the public and generated ongoing requests for a folding version. We call the folding version the Yojimbo and feel it defines the term ergonomic. Since Mr. Janich's area of expertise is MBC and Filipino martial arts, the folder was designed around that art form.

The blade is categorized as a modified Wharncliffe profile. Purposely designed to be triangular, this shape holds the cutting edge in contact with what is being cut, and its fine sharp tip generates little resistance initiating and making piercing cuts. From a tactical standpoint the blade's steel needed to be tough and resistant to wear so we chose CPM-S30V. We then ground the cutting edge fully flat from the tip to where it meets the handle. Lined up running along the blade's spine are a sequence of thumb positioning serrations/grooves that continue into the spine of the handle. The Yojimbo's G-10 handle fills in the palm like a handshake affording heightened dexterity and control over the blade. Its tapered tail is for grip retention and doubles as a pressure point or striking tool. To be used for the rigors of MBC a strong lock was a requirement so nested into the handle scale is a Compression Lock that releases on top of the handle. All-steel pocket clip attaches for right-hand, tip-up mobility. The circles, cut out of the clip and on the opposite side of the handle, are for indexing. Available with a black or blue handle."[1]